A Study of Flow Properties of Kuwaiti Crude Oil Obtained from Different Sources

The rheological properties of four different Kuwaiti crude oils in the presence of polyacrylamide (PAA) were investigated. PAA was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. Four different temperatures (25, 30, 35, and 40 °C) were used to evaluate different viscoelastic parameters of the treated and untreated Kuwaiti crude oils. The sulfur content and physical properties; such as, density and refractive index of Kuwaiti crude oils were also measured. An important observation noted from the rheological analysis is that the dynamic viscoelastic parameters like complex modulus, elastic modulus, and storage modulus were found to be a function of the amount of sulfur present in the crude oil. The most important observation noted is that PAA acts as a drag reducing agent in lowering the viscosity, shear stress, and all the viscoelastic parameters of the Kuwaiti crude oil. Carreau model was used in this investigation to determine the relaxation time and the shear thinning characteristics of the treated and untreated crude oil samples at different temperatures

Dust effect on PV modules

This paper investigates the effect of dust on photovoltaic (PV) modules with respect to dust concentration, wavelength and spectral transmittance. Dust samples were collected from Kuwait in the form of raw dust and accumulated dust on sample glass at different tilt angles. The spectral transmittance was measured in the Centre for Renewable Energy Systems Technology (CREST) laboratory with a spectrophotometer. Spectral transmittance variation was identified for samples at different tilted positions, where the worst case was presented at a tilt angle of 30o with a non uniformity of 4.4% in comparison to 0.2% for the 90o tilt between the top, middle and bottom. The effect of this on PV is investigated by calculating a modified spectral response for different technologies using spectral response data measured by the European Solar Test Installation (ESTI). The measured data showed a faster rate of decrease in transmittance at wavelengths <570 nm. This affects wide band-gap technologies more than crystalline silicon technologies and especially amorphous silicon which showed a 33% reduction in the spectral photocurrent when a dust concentration of 8.5 mg/cm2 was applied. In comparison, the crystalline silicon and copper indium gallium diselenide (CIGS) technologies showed 28.6% and 28.5% reductions at the same dust density

Effect of dust shading on photovoltaic modules

This paper investigates the effect of dust on photovoltaic (PV) modules with respect to dust concentration and spectral transmittance. Dust samples were collected from Kuwait in the form of raw dust and accumulated dust on sample glasses at different tilt angles. The spectral transmittance was measured at the Centre for Renewable Energy Systems Technology (CREST) laboratory with a spectrophotometer. Total transmittance variation was identified for samples at different tilted positions, where the worst case was presented at a tilt angle of 30o with a non uniformity of 4.4% in comparison to 0.2% for the 90o tilt between the top, middle and bottom. Finally the data was translated to an effective spectral response for different technologies using spectral response data measured by the European Solar Test Installation (ESTI). The measured data showed a decrease in transmittance at wavelengths <570 nm. This affects wide band-gap thin-film technologies more than crystalline silicon technologies and especially amorphous silicon which showed a 33% reduction in photocurrent when a dust concentration of 4.25 mg/cm2 was applied. In comparison, the crystalline silicon and CIGS technologies showed 28.6% and 28.5% reductions at the same dust density

A Nature Inspired Approach for Enhancing the Efficacy of Anticancer Agents

Ligand-targeted therapeutics are a rapidly growing class of anticancer agents. This class of therapeutics is typically bifunctional molecules that use a targeting moiety to selectively deliver potent, typically nonspecific, cytotoxic agents to cancer cells while sparing normal cells. The low-molecular-weight of ligant-targeted therapeutics allows for better tumor penetration, especially in the case of solid tumors where the size of antibodies is a limiting factor for effective treatment. Unfortunately, the poor pharmacokinetic profiles of many of these conjugates present a challenge, which limits their tremendous therapeutic potential. Dose-limiting toxicity is also observed due to the need for high doses and frequent administration. This dissertation describes our work to develop a fundamentally new approach for targeting cancer. Our approach could potentially reduce the toxicity and enhance the pharmacokinetic properties of targeted anticancer agents, which would decrease dosing frequency and improve the lives of cancer patients

A Nature Inspired Approach for Enhancing the Efficacy of Anticancer Agents

Ligand-targeted therapeutics are a rapidly growing class of anticancer agents. This class of therapeutics is typically bifunctional molecules that use a targeting moiety to selectively deliver potent, typically nonspecific, cytotoxic agents to cancer cells while sparing normal cells. The low-molecular-weight of ligant-targeted therapeutics allows for better tumor penetration, especially in the case of solid tumors where the size of antibodies is a limiting factor for effective treatment. Unfortunately, the poor pharmacokinetic profiles of many of these conjugates present a challenge, which limits their tremendous therapeutic potential. Dose-limiting toxicity is also observed due to the need for high doses and frequent administration. This dissertation describes our work to develop a fundamentally new approach for targeting cancer. Our approach could potentially reduce the toxicity and enhance the pharmacokinetic properties of targeted anticancer agents, which would decrease dosing frequency and improve the lives of cancer patients

Rapid modeling of borehole measurements of nuclear magnetic resonance via spatial sensitivity functions

Borehole measurements of Nuclear Magnetic Resonance (NMR) are routinely used to estimate in situ rock and fluid properties. Conventional NMR interpretation methods often neglect bed-boundary, mud-filtrate invasion, layer-thickness, and layer-dip effects in the calculation of fluid volumetric concentrations and NMR relaxation-diffusion correlations. Such effects introduce notable spatial averaging of intrinsic rock and fluid properties across thinly-bedded formations or in the vicinity of boundaries between layers exhibiting large property contrasts. Furthermore, the interpretation of NMR measurements entails major technical challenges in horizontal layers penetrated by high-angle and horizontal wells (HAHz) or across dipping layers penetrated by a vertical well. Three-dimensional (3D) geometrical effects, coupled with spatially and petrophysically heterogeneous rocks, may bias petrophysical estimates obtained from borehole NMR measurements when using interpretation procedures designed for vertical wells and horizontal layers. Forward modeling and inversion methods can mitigate the aforementioned effects and improve the accuracy of true layer properties in the presence of mud-filtrate invasion and borehole environmental and 3D geometrical effects across spatially complex formations. This dissertation introduces a fast and accurate algorithm to simulate borehole NMR measurements using the concept of spatial sensitivity functions (SSFs) that honor NMR physics and explicitly incorporate tool, borehole, and geometrical properties. To that end, a 3D multiphysics forward model is developed that couples NMR tool properties, magnetization time evolution, and electromagnetic propagation to derive the 3D spatial sensitivity maps associated with a specific borehole instrument. Additionally, a multifluid relaxation model based on Brownstein-Tarr’s equation is introduced to estimate layer-by-layer NMR porosity decays and relaxation-diffusion correlations from pore-size-dependent rock and fluid properties. The latter model is convolved with the SSFs to reproduce borehole NMR measurements acquired with advanced pulsing sequences (e.g., diffusion-editing and saturation recovery sequences). Results indicate that the spatial sensitivity of NMR measurements is controlled by porosity, electrical conductivity, excitation pulse duration, and tool geometry. The SSF-derived forward approximation is benchmarked and verified against 3D multiphysics simulations for a series of synthetic cases with variable bed thickness and petrophysical properties, as well as in the presence of mud-filtrate invasion. It is shown that the approximation can be executed in a few seconds of central processing unit (CPU), by a factor of 1000 times faster than rigorous multiphysics calculations, with maximum root-mean- square errors (RMSE) of 1%. On average, the fast approximation via SSFs reproduces borehole NMR measurements in 0.08 seconds of CPU time per logging measurement and can therefore be used for real-time calculations and interpretations. Next, the NMR forward modeling approximation is implemented to simulate measurements acquired across dipping formations penetrated by deviated wells in the presence of mud-filtrate invasion. Borehole NMR measurements are simulated by transforming a dipping layered model penetrated by an arbitrary well trajectory into an apparent layered model probed by a vertical well. This work compares the effect of radial length of investigation (DOI) from the three distinct NMR acquisition shells at 3.81 cm (1 in), 6.35 cm (2.5 in) and 10.16 cm (4 in), to integrate borehole NMR measurements acquired in 3D complex geometries. It is found that thinly-bedded formations and their petrophysical properties can be resolved with limited measurement resolution in HAHz wells and highly dipping formations. In thinly-bedded layers (e.g., thinner than 0.15 m) probed by a vertical well, spatial averaging effects bias the NMR porosity logs acquired with high vertical resolution (e.g., sampling rate equals to 2.54 cm). Conversely, formation geometrical and petrophysical properties can be accurately estimated across high apparent-dip formations. It is found that the shallower NMR acquisition shell (3.81 cm) is the least affected by bed-boundary averaging with increasing apparent dip. Moreover, the increase in apparent dip shifts the location of apparent bed boundaries. The latter phenomenon is more pronounced at deeper radial DOI. Interpretation procedures must mitigate such geometrical effects to accurately detect true bed boundaries and estimate layer-by-layer petrophysical propertiesPetroleum and Geosystems Engineerin

Studying the Effect of Aluminum Oxides Composition and Particle Size on the Mechanical Properties of Metal-TiC Composite for Different Heat Treatment Process

&lt;p&gt;The composites design goals to have combined properties of each of the materials component. Different materials composition between metals, ceramics, and polymers can change the composite properties. In this research, metal matrix composite was selected to be aluminum as matrix phase while the reinforced materials were selected to be Nano particles Titanium carbide and different volume percentage of aluminum oxides (whiskers). All specimens were fabricated one time by annealing and another time by hardening heat treatment process. It was found that the heat treatment process, Alumina particle sizes, and Alumina weight percentage have sever and significant effect on the measured mechanical properties; ultimate tensile, compressive strength and hardness of the metal composite while it have minor effect on the material ductility represented in the measured elongation percentage.&lt;/p&gt;&lt;p&gt;Keywords:- Metallic composite, metal matrix, Titanium carbide, Aluminum oxide particle size, Reinforced material,&lt;/p&gt

Dust Effects on PV Modules

This paper investigates the effect of dust on photovoltaic (PV) modules with respect to dust concentration, wavelength and spectral transmittance. Dust samples were collected from Kuwait in the form of raw dust and accumulated dust on sample glass at different tilt angles. The spectral transmittance was measured in the Centre for Renewable Energy Systems Technology (CREST) laboratory with a spectrophotometer. Spectral transmittance variation was identified for samples at different tilted positions, where the worst case was presented at a tilt angle of 30° with a non uniformity of 4.4% in comparison to 0.2% for the 90° tilt between the top, middle and bottom. The effect of this on PVjs investigated by calculating a modified spectral response for different technologies using spectral response data measured by the European Solar Test Installation (ESTI). The measured data showed a faster rate of decrease in transmittance at wavelengths <570 nm. This affects wide band-gap technologies more than crystalline silicon technologies and especially amorphous silicon which showed a 33% reduction in the spectral photocurrent when a dust concentration of 8.5 mg/cm 2 was applied. In comparison, the crystalline silicon and copper indium gallium diselenide (CIGS) technologies showed 28.6% and 28.5% reductions at the same dust density.JRC.F.8-Renewable Energy (Ispra

Dust-induced shading on photovoltaic modules

The effect of dust on photovoltaic (PV) modules is investigated with respect to concentration and spectral transmittance. Samples were collected in the form of raw dust as well as accumulated dust on exposed sheets of glass at different tilt angles. Spectral transmittance of the samples was determined. Transmittance variation between top, middle and bottom was identified for samples collected at different inclinations, where the worst case was seen at a tilt angle of 30o with a non uniformity of 4.4% in comparison to 0.2% for the 90o tilt. The measured data showed a decrease in transmittance at wavelengths <570 nm. Integrating this with measured spectral responses of different technologies demonstrates that wide band-gap thin-film technologies are affected more than e.g. crystalline silicon technologies. The worst case is amorphous silicon, where a 33% reduction in photocurrent is predicted for a dust concentration of 4.25 mg/cm2. Crystalline silicon and CIGS technologies are predicted to be less affected, with 28.6% and 28.5% reductions in photocurrent respectively. The same procedure was repeated with varying Air Mass (AM), tilt angle and dust concentration values to produce a soiling ratio table for different technologies under different AM, tilt angle and dust concentration values.JRC.F.7-Renewable Energ

Dust Effect on PV Modules

This paper investigates the effect of dust on photovoltaic (PV) modules with respect to dust concentration, wavelength and spectral transmittance. Dust samples were collected from Kuwait in the form of raw dust and accumulated dust on sample glass at different tilt angles. The spectral transmittance was measured in the Centre for Renewable Energy Systems Technology (CREST) laboratory with a spectrophotometer. Spectral transmittance variation was identified for samples at different tilted positions, where the worst case was presented at a tilt angle of 30o with a non uniformity of 4.4% in comparison to 0.2% for the 90o tilt between the top, middle and bottom. The measured data showed a faster rate of decrease in transmittance at wavelengths <570 nm. This affects thin-film technologies more than crystalline silicon technologies and especially amorphous silicon which showed a -33% reduction in the spectral photocurrent when a dust concentration of 8.5 mg/cm2 was applied. In comparison, the crystalline silicon and CIGS technologies showed -28.6% reductions at the same dust density.JRC.F.7-Renewable Energ